adding more related logs scripts

shell_scripts/logs_extract_last_month

@@ -0,0 +1,3 @@
+#! /usr/bin/env bash
+MONTH=`date +%m --date "a month ago"`
+grep "^$MONTH-" \##pim.log > $MONTH-pim.log

shell_scripts/logs_monthly_stats

@@ -0,0 +1,2 @@
+#! /usr/bin/env bash
+wc -l 20{09,10,11}-* | grep -v total | sed "s/ 2010.*//" | sed "s/ 2009.*//" | sed "s/ 2011.*//" > monthly_lines.data